Question

I was walking in the park and heard a scream, then a girl slammed down. I quickly ran to the girl's side and found out that she was dead. After that, I saw a male student on the 5th floor looking at this place. I think the murderer should be him.

The police then arrested the male student. The student said:

I walking at upstairs that afternoon and suddenly heard screams, so I rushed over. I found that the handrails on the 5th floor fell off. So, I looked down and saw a girl lying on the floor. Then I saw that the teacher was looking at me too.

30 minutes later, police found a note inside the victim's drawer which wrote:

Do you want to know what happened to you? See you at the balcony at 5 pm.

Police also found a broken eyeglass at the crime scene. After comparison, this eyeglass prescription is much higher than the eyeglass in the victim's house.

According to her classmates, except for the class, she does not wear glasses. According to the family, she had lost her memory, she goes to the 5th floor because of the note.